SLAC Today is
available online at:http://today.slac.stanford.eduIn this issue:
New Project Tools to Coordinate ILC Design
Science Today: Busy Times for BaBar
Bicycle Safety at SLAC's Main Gate

Thursday - August 23, 2007

New Project Tools to Coordinate ILC Design

A drawing of the fourth generation cryomodule being co-designed by DESY, Fermilab and INFN using the
ILC EDMS. The cryomodule houses the accelerating structures, liquid Helium, heat shields, and other components.

by Heather Rock Woods

International Linear Collider (ILC) researchers from around the globe are beginning the project's engineering design with a new set of tools that will allow decentralized collaborators to work in concert.

The project tools now in place follow the recommendations of the Global Design Effort's selection committee chaired by SLAC's Tom Markiewicz.

"I wholeheartedly thank the committee and dismiss them following a job very well done,"
Global Design Effort Director Barry Barish wrote in
ILC NewsLine.

"Together, these three tools will allow far-flung collaborators to work together effectively as we enter the engineering phase of the project," Markiewicz said.

Collaboration teams and committees can contribute project information to shared workspaces, and view, revise or approve information posted by colleagues. The EDMS should make many tasks easier because it
requires that designs use the exact same version of each component, whether a flange or an accelerator structure. This allows remote collaborators to improve the design for a particular component, or use a component in part of a larger structure, knowing they are using the right pieces.

Busy Times for BaBar

by Mathew Graham

It's been another busy and successful year for BaBar. The B-factory presented an impressive 48 new results at the Lepton-Photon conference in Daegu,
South Korea, including some using the most recent Run-6 data. The new
results spanned the BaBar physics spectrum and included new measurements of Charge Parity (CP) violation in B-decays, decay rates of
τ-leptons, and the search for new charm and charmonium
states.

Undoubtedly the most exciting development over the past year has been the
observation of
mixing in the neutral D-meson (symbolized by D0), first announced by BaBar in March and confirmed by Belle soon after (see a recent
SLAC Today article by JoAnne Hewett for an interesting discussion on the implications of this discovery). The discovery of
D0 mixing, thought unobtainable when the B-Factories began, was first achieved in the decays of D-mesons to K-
and π-mesons. Since the spring, these first measurements have been confirmed by measurements of mixing in other channels including the three-body decay modes and in the lifetime measurements of decays into two K-mesons and two
π-mesons, all of which were presented in Daegu. The mixing results have generated significant theoretical interest as well with a recent search on SLAC-SPIRES yielding a large number of citations to the original BaBar paper.

BaBar has also continued work on measuring the
Unitarity Triangle
of the Cabibbo-Kobayashi-Maskawa (CKM)
matrix, an important test of the Standard Model. At the Lepton-Photon
conference, new measurements on all of the sides and angles were presented.In particular, for the first time BaBar has measured the CP-asymmetries in B0 decays to two neutral rho mesons (denoted
ρ0), a key ingredient in extracting the Unitarity Triangle angle
α. The angle α is one of the three critical quantities that allow the B-factory experiments to probe the complex phase of the CKM matrix.
Read more...

ATLAS Workshop Photos Now Online

Bicycle Safety atSLAC's Main Gate

Cyclists entering SLAC's main gate have two options: either merging into
the left-hand turn lane, or turning right onto Saga Lane and then making
a U-turn to cross.(Click on image for larger version.)

Making a left hand turn on a busy four lane road can be a dangerous maneuver on a bicycle, yet it's something that hundreds of SLAC employees and users do every day as they turn off Sand Hill Road and into SLAC's main gate.

The practice of making a right-hand turn, making a U-turn, and then using a traffic light to cross a major thoroughfare is a common practice in bicycle-friendly cities throughout the world. When traffic is dense and moving quickly, this tactic can be safer than crossing from the bicycle lane into the left turn lane. However, cyclists should beware of traffic overtaking them before executing the U-turn; making use of the full lane can mitigate this problem.

The traffic light at the intersection of Sand Hill Road and Saga Lane supports this maneuver. Traffic leaving SLAC and Saga Lane gets a green light prior to traffic turning left from Sand Hill Road into SLAC. As a result, if the Saga Lane vehicle detector senses a cyclist, this cyclist has priority to cross Sand Hill Road over vehicles making a left-hand turn from Sand Hill Road. This is to encourage cyclists to use the bicycle-friendly vehicle detector on Saga Lane and cross with the traffic light instead of crossing two lanes of fast-moving traffic. It is faster for the cyclists, and the added benefit is that most cyclists will clear the main gate before the left-turning cars, thereby reducing cycle/auto interference up the hill.